1. Field of the Invention
The invention relates generally to the field of computer-aided diagnostic (CAD) schemes in chest radiography. The present invention also generally relates to computerized techniques for automated analysis of digital images, for example, as disclosed in one or more of U.S. Pat. Nos. 4,839,807; 4,841,555; 4,851,984; 4,875,165; 4,907,156; 4,918,534; 5,072,384; 5,133,020; 5,150,292; 5,224,177; 5,289,374; 5,319,549; 5,343,390; 5,359,513; 5,452,367; 5,463,548; 5,491,627; 5,537,485; 5,598,481; 5,622,171; 5,638,458; 5,657,362; 5,666,434; 5,673,332; 5,668,888; 5,732,697; 5,740,268; 5,790,690; 5,832,103; 5,873,824; 5,881,124; 5,931,780; 5,974,165; 5,982,915; 5,984,870; 5,987,345; and 6,011,862; as well as U.S. patent application Ser. Nos. 08/173,935; 08/398,307 (PCT Publication WO 96/27846); Ser. Nos. 08/536,149; 08/562,087; 08/900,188; 08/900,189; 08/900,191; 08/900,361; 08/979,623; 08/979,639; 08/982,282; 09/027,468; 09/027,685; 09/028,518; 09/053,798; 09/092,004; 09/121,719; 09/131,162; 09/141,535; 09/156,413; 09/298,852; and 09/471,088; PCT patent applications PCT/US99/24007; PCT/US99/25998; and U.S. provisional patent applications No. 60/160,790 all of which are incorporated herein by reference.
The present invention includes use of various technologies referenced and described in the above-noted U.S. Patents and Applications, as well as described in the references identified in the appended LIST OF REFERENCES by the author(s) and year of publication and cross-referenced throughout the specification by numerals in brackets corresponding to the respective references, the entire contents of which, including the related patents and applications listed above and references listed in the LIST OF REFERENCES, are incorporated herein by reference.
2. Discussion of the Background
A recent trend toward increased practical use of picture archiving and communication systems (PACS) in many hospitals and medical centers is very likely to expedite clinical applications of computer-aided diagnostic (CAD) schemes in chest radiography. The PACS has been used as an image management system for improving the efficiency of radiology department, in some medical centers and hospitals. For maintaining reliability of the PACS, incorrect images and incorrect patient data should not be stored in the PACS. However, if the patient information associated with an image, such as the identification number or the patient name, has been entered incorrectly, the image will be stored in an incorrect patient folder, and it is difficult to find this error. During routine image interpretation, it is not uncommon that radiologists occasionally recognize a wrong patient""s image which is displayed in a series of images for a given patient.
Accordingly, due shortcomings in the above-noted methods, it is desirable to develop a more reliable method for correct identification a patient""s chest images.
In addition, for quantitative analysis of chest radiographs, such as computerized detection of lung nodules [1, 2] and interstitial infiltrates [3, 4] as well as temporal subtraction [5, 6] of a previous image from a current image, it is typically necessary to identify either posteroanterior (PA) or lateral views of chest images because the computerized scheme depends on the specific view used. [7, 8]
However, in PACS or digital archiving systems, the information on the PA and lateral views for chest radiographs is often not recorded. Although the digital imaging and communications in medicine (DICOM) standard can include such labeling and many other parameters, most of this useful information is commonly not entered, or incorrect data are stored occasionally.
Recently, artificial neural networks have been applied for the automatic labeling (i.e., PA or lateral) and orientation of chest images, and the reported accuracy is 98.7% for correcting labeling errors. [9]
However, due shortcomings in the above-noted methods, it is desirable to develop a more reliable method for identification of correct views of chest images.
Accordingly, an object of this invention is to provide a method, system and computer readable medium for a computer-automated method for correctly identifying an image as belonging to a given patient.
Another object of the invention is to provide a method, system and computer readable medium for a computer-automated method for correctly identifying an image as belonging to a given patient using a current and previous image of the patient.
Another object of the invention is to provide a method, system and computer readable medium for a computer-automated method for correctly identifying whether image data derived from a chest radiograph is representative of a PA view or a lateral view of a subject.
Another object of the invention is to provide a method, system and computer readable medium for a computer-automated method for examining whether image data of a given chest image is similar to data derived from image of PA or lateral views of a subject.
Another object of the invention is to provide a method, system and computer readable medium for a computer-automated method for measuring the similarity of two images by determining a cross-correlation coefficient (hereafter referred to as xe2x80x9ccorrelation valuexe2x80x9d) between image data of a template and image data of a given chest image.
These and other objects are achieved according to the invention by providing a new automated method, system and computer readable medium for identifying given image data, including obtaining template image data corresponding to the given image data; calculating correlation values between the given image data and the template image data; and identifying the image data based on the correlation values calculated in the calculating step.
The present invention accordingly includes a computer readable medium storing program instructions by which the method of the invention can be performed when the stored program instructions are appropriately loaded into a computer, and a system for implementing the method of the invention.